Bone grafts and biomaterials substitutes for bone defect repair: A review.

A new method for the treatment of scoliosis is described in which a metal system of rods and hooks is implanted, and distraction and compression forces applied, to correct the curve and stabilize the treated segments in the corrected position by skeletal fixation. The technique and principles of this method of treatment and a summary of the preliminary results are given.

JBJS classics: Treatment of scoliosis: Correction and internal fixation by spine instrumentation

Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes. Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans. 227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure. 3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D-printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost–effectiveness analysis.

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3D-printing techniques in a medical setting: a systematic literature review

Advantages and disadvantages of 3-dimensional printing in surgery: A systematic review.

In seven strains of cultured normal human osteoblast-like cells, a mean of 1615 molecules of tritium-labeled 17 beta-estradiol per cell nucleus could be bound to specific nuclear sites. The nuclear binding of the labeled steroid was temperature-dependent, steroid-specific, saturable, and cell type-specific. These are characteristics of biologically active estrogen receptors. Pretreatment with 10 nanomolar estradiol in vitro increased the specific nuclear binding of progesterone in four of six cell strains, indicating an induction of functional progesterone receptors. RNA blot analysis demonstrated the presence of messenger RNA for the human estrogen receptor. The data suggest that estrogen acts directly on human bone cells through a classical estrogen receptor-mediated mechanism.

Evidence of estrogen receptors in normal human osteoblast-like cells

Object. Osteoporotic vertebral fractures occasionally lead to late-onset collapse, kyphosis, persistent back pain, and disability. The authors describe a series of patients in whom they performed percutaneous vertebroplasty by using calcium phosphate cement (CPC) to obtain early pain relief and improve the integrity of the osteoporotic vertebral body (VB). Methods. Between August 2000 and February 2001, they performed 17 percutaneous transpedicular CPC-assisted vertebroplasty procedures in 16 patients who harbored thoracic or lumbar osteoporotic vertebral fractures. Following repositioning and curettage of the pathological soft tissues, CPC-assisted vertebroplasty was percutaneously performed in four patients with osteoporotic burst fracture and pseudarthrosis (Procedure A). In situ CPC-assisted vertebroplasty was performed in 12 patients with fresh vertebral compression fractures due to osteoporosis (Procedure B). Back pain and low-back pain were evaluated using a visual analog scale (VAS). The deformity...

Percutaneous transpedicular vertebroplasty with calcium phosphate cement in the treatment of osteoporotic vertebral compression and burst fractures.

Study design A prospective cohort study Objective To evaluate ossification of the posterior longitudinal ligament (OPLL) of the whole spine in patients with cervical OPLL and to analyze which types of cervical OPLL were associated with the other lesions in the thoracic and/or lumbar spine Summary of background data OPLL is most frequently seen in the cervical spine The coexisting ossified lesions are sometimes observed in other spinal regions However, coexisting OPLL in other spinal regions have not yet been precisely evaluated in patients with cervical OPLL Methods One hundred seventy-eight patients with a diagnosis of cervical OPLL whose plain radiographs were obtained were included Computed tomographic images of the whole spine were obtained The ossification index (OS index) was newly determined according to the sum of the levels of vertebral bodies and intervertebral discs with OPLL The patients were divided into 2 groups, the group that had OPLL only in the cervical spine (C group) and the group that had OPLL in multilevel spinal regions other than the cervical spine (M group) Results Ninety-five (534%) had OPLL not only in the cervical spine, but also in other spinal regions The M group had more females than the C group The incidence of bridge formation in the cervical spine was higher in M group than in C group More females had a high OS index A positive correlation was found between the OS index of the cervical spine and the OS index of the thoracic and lumbar spine; however, the r value was small Conclusion This study demonstrated that more than half of the patients with cervical OPLL had coexisting OPLL in the thoracic and/or lumbar spine We strongly recommend computed tomographic analysis of the whole spine for patients with radiographical evidence of OPLL in the cervical spine for the early detection of additional sites of ossification

Ossification of the posterior longitudinal ligament in not only the cervical spine, but also other spinal regions: analysis using multidetector computed tomography of the whole spine.

Study design We developed a new technique for cervical pedicle screw and Magerl screw insertion using a 3-dimensional image guide. Objective In posterior cervical spinal fusion surgery, instrumentation with screws is virtually routine. However, malpositioning of screws is not rare. To avoid complications during cervical pedicle screw and Magerl screw insertion, the authors developed a new technique which is a mold shaped to fit the lamina. Summary of background data Cervical pedicle screw fixation and Magerl screw fixation provide good correction of cervical alignment, rigid fixation, and a high fusion rate. However, malpositioning of screws is not a rare occurrence, and thus the insertion of screws has a potential risk of neurovascular injury. It is necessary to determine a safe insertion procedure for these screws. Methods Preoperative computed tomographic (CT) scans of 1-mm slice thickness were obtained of the whole surgical area. The CT data were imported into a computer navigation system. We developed a 3-dimensional full-scale model of the patient's spine using a rapid prototyping technique from the CT data. Molds of the left and right sides at each vertebra were also constructed. One hole (2.0 mm in diameter and 2.0 cm in length) was made in each mold for the insertion of a screw guide. We performed a simulated surgery using the bone model and the mold before operation in all patients. The mold was firmly attached to the surface of the lamina and the guide wire was inserted using the intraoperative image of lateral vertebra. The proper insertion point, direction, and length of the guide were also confirmed both with the model bone and the image intensifier in the operative field. Then, drilling using a cannulated drill and tapping using a cannulated tapping device were carried out. Eleven consecutive patients who underwent posterior spinal fusion surgery using this technique since 2009 are included. The screw positions in the sagittal and axial planes were evaluated by postoperative CT scan to check for malpositioning. Results The screw insertion was done in the same manner as the simulated surgery. With the aid of this guide the pedicle screws and Magerl screws could be easily inserted even at the level where the pedicle seemed to be very thin and sclerotic on the CT scan. Postoperative CT scan showed that there were no critical breaches of the screws. Conclusion This method employing the device using a 3-dimensional image guide seems to be easy and safe to use. The technique may improve the safety of pedicle screw and Magerl screw insertion even in difficult cases with narrow sclerotic pedicles.

Development of a New Technique for Pedicle Screw and Magerl Screw Insertion Using a 3-Dimensional Image Guide

Object Few studies have been conducted to compare vertebroplasty and conservative treatment for osteoporotic vertebral compression fractures (OVCFs). To investigate the effects of calcium phosphate cement (CPC)–based vertebroplasty on relief of pain and augmentation of the fractured vertebral body (VB), the authors compared the results of CPC-assisted vertebroplasty with those of conservative treatment alone. Methods Two groups of patients were examined: the vertebroplasty group (30 consecutive patients with primary OVCF) and the control group (30 patients matched for age, sex, interval from injury to treatment, and grade of the posterior wall defects of the fractured VB). Outcome measures included the visual analog scale (VAS) score of back pain and analgesic requirements, and the radiographically documented rate of the VB kyphosis. The follow-up duration was more than 12 months (mean 17 months). The mean VAS score at 12 months after injury was 0.67 cm in the vertebroplasty group and 1.97 cm in the contr...

Calcium phosphate cement–based vertebroplasty compared with conservative treatment for osteoporotic compression fractures: a matched case–control study

Characteristics of ossification of the spinal ligament; incidence of ossification of the ligamentum flavum in patients with cervical ossification of the posterior longitudinal ligament – Analysis of the whole spine using multidetector CT

Masato Nakano

Papers

Percutaneous transpedicular vertebroplasty with calcium phosphate cement in the treatment of osteoporotic vertebral compression and burst fractures.

Ossification of the posterior longitudinal ligament in not only the cervical spine, but also other spinal regions: analysis using multidetector computed tomography of the whole spine.

Development of a New Technique for Pedicle Screw and Magerl Screw Insertion Using a 3-Dimensional Image Guide

Calcium phosphate cement–based vertebroplasty compared with conservative treatment for osteoporotic compression fractures: a matched case–control study

Characteristics of ossification of the spinal ligament; incidence of ossification of the ligamentum flavum in patients with cervical ossification of the posterior longitudinal ligament – Analysis of the whole spine using multidetector CT